Stream: git-wasmtime

Topic: wasmtime / issue #13856 `Winch internal error: Unsupporte...

view this post on Zulip Wasmtime GitHub notifications bot (Jul 09 2026 at 20:24):

fitzgen opened issue #13856:

To repro, clone Sightglass and run this command in the Wasmtime repo:

$ cargo run -- compile -C compiler=winch -- path/to/sightglass/benchmarks/meshoptimizer/benchmark.wasm
Error: failed to compile: wasm[0]::function[14]

Caused by:
    Compilation error: Winch internal error: Unsupported immediate

It also fails on a few of the libsodium benchmarks, maybe others as well.

+cc @saulecabrera

view this post on Zulip Wasmtime GitHub notifications bot (Jul 09 2026 at 20:24):

fitzgen added the winch label to Issue #13856.

view this post on Zulip Wasmtime GitHub notifications bot (Jul 10 2026 at 14:00):

saulecabrera commented on issue #13856:

Thanks Nick; I will take a look.

view this post on Zulip Wasmtime GitHub notifications bot (Jul 16 2026 at 14:16):

saulecabrera commented on issue #13856:

I am able to reproduce this one. Can you confirm that this one only fails on Aarch64 on your end? I was not able to reproduce on x86_64. If so, this is expected, since the Aarch64 backend does not offer support for [SIMD], yet. However, the error could be better here, I have opened https://github.com/bytecodealliance/wasmtime/pull/13889 to improve the error message.

[SIMD]: https://github.com/bytecodealliance/wasmtime/issues/9925

view this post on Zulip Wasmtime GitHub notifications bot (Jul 20 2026 at 16:07):

fitzgen commented on issue #13856:

Can you confirm that this one only fails on Aarch64 on your end?

Yes, I was on aarch64, haven't tried x64, but if you say it doesn't reproduce there then I believe it. There wasn't anything fancy about reproducing involved.

view this post on Zulip Wasmtime GitHub notifications bot (Jul 20 2026 at 16:07):

fitzgen closed issue #13856:

To repro, clone Sightglass and run this command in the Wasmtime repo:

$ cargo run -- compile -C compiler=winch -- path/to/sightglass/benchmarks/meshoptimizer/benchmark.wasm
Error: failed to compile: wasm[0]::function[14]

Caused by:
    Compilation error: Winch internal error: Unsupported immediate

It also fails on a few of the libsodium benchmarks, maybe others as well.

+cc @saulecabrera

view this post on Zulip Wasmtime GitHub notifications bot (Jul 20 2026 at 16:07):

fitzgen commented on issue #13856:

I think this can be closed now

Last updated: Jul 29 2026 at 05:03 UTC